The Duke Medical Center proposes the establishment of a Laboratory for development of Health Information Systems which wll develop an information system that will supply the practicing physician with information of a kind and quality which is not available to him at the present time. The practicing doctor will define the descriptors which describe his current patient and search of the data bank will supply him with information on the patients who have these same descriptors and their outcome. The data bank will be built by the staff on the Duke Medical Center, but it can be used by any health professional. To build and use this bank, the following components are necessary: a) physician leadership in developing and using the data base, b) strong bioengineering inputs so that more and more clinical data can be expressed in numerical terms, c) the development of hardware and software so that the data base in the medical center can be be used in every doctor's office at a level of expense tolerable to third-party providers.